1. Field of the Invention
The present invention is broadly directed to a method for treating human T cell lymphotrophic virus type 1 (HTLV-1) infection. In particular, the invention is directed to a method for inhibiting the induced effects of HTLV-1 viral protein activity such as Tax 1 activity and for inhibiting replication of HTLV-1. The present invention is particularly directed to the use of a particular class of isozyme selective Protein Kinase C (PKC) inhibitors for treating HTLV-1 infection and the diseases associated therewith such as T cell leukemia and HTLV-1 induced central nervous system disorder.
2. Description of Related Art
People infected with human T cell lymphotrophic virus type 1 (HTLV-1) are prone to developing adult T cell leukemia. In addition, HTLV-1 infected individuals can manifest chronic neurodegenerative illnesses such as tropical spastic paraparesis and myelopathy. No particular treatment for HTLV-1 infection is available in the art. Treatment for diseases associated with HTLV-1 infection is symptomatic and does not provide satisfactory results. Therefore, there remains a need in the art to develop therapeutic agents for treatment of HTLV-1 infection and the diseases associated therewith.
Leukemia is a disease characterized by neoplastic proliferation of one of the blood-forming cells. The different types of leukemia are classified according to the cell type involved, and as acute or chronic, depending on the duration of the disease. If left untreated, all forms of leukemia are fatal. Death is usually due to complications resulting from infiltration of the bone marrow by leukemic cells and replacement of normal hematopoietic cells. Adult T cell leukemia may be associated with HTLV-1 infection. During the last quarter century, a worldwide effort has been mounted to improve the treatment of leukemia. Using the best current treatment regimens, over 90 percent of children with acute lymphoblastic leukemia (ALL) now achieve complete remission. However, adults with ALL, especially T cell leukemia, generally respond less favorably to treatment than children, and most trials have resulted only in complete remission rates of 50 percent or less, and only with a median duration of a year or less. Therefore, there is a continuing need in the art to develop new therapeutic agents for treatment of adult T cell leukemia associated with HTLV-1 infection.
HTLV-1 infection also can cause chronic neurodegenerative disorders. Chronic neurodegenerative illnesses such as tropical spastic paraparesis and myelopathy may cause loss of function, suppression of reflex activity, and other complications. In general, the treatment for neurodegenerative disorders is conservative and symptomatic without complete recovery. Thus, there also is a need in the art to develop new therapeutic agents for treatment of chronic neurodegenerative disorders associated with HTLV-1 infection.